如何分离CSV文件中特定列的变量并写入R中的CSV文件？

Question

我有一个像CSV的文件

Market,CampaignName,Identity
Wells Fargo,Gary IN MetroChicago IL Metro,56
EMC,Los Angeles CA MetroBoston MA Metro,78
Apple,Cupertino CA Metro,68

所需输出到CSV文件,第一行作为标题

Market,City,State,Identity
Wells Fargo,Gary,IN,56
Wells Fargo,Chicago,IL,56
EMC,Los Angeles,CA,78
EMC,Boston,MA,78
Apple,Cupertino,CA,68

res <- 
  gsub('(.*) ([A-Z]{2})*Metro (.*) ([A-Z]{2}) .*','\\1,\\2:\\3,\\4',
  xx$Market)

如何修改上面的正则表达式以获得R中的结果？R的新手,任何帮助表示赞赏.

Answer 1

library(stringr)
xx.to.split <- with(xx, setNames(gsub("Metro", "", as.character(CampaignName)), Market))
do.call(rbind, str_match_all(xx.to.split, "(.+?) ([A-Z]{2}) ?"))[, -1]

生产:

            [,1]          [,2]
Wells Fargo "Gary"        "IN"
Wells Fargo "Chicago"     "IL"
EMC         "Los Angeles" "CA"
EMC         "Boston"      "MA"
Apple       "Cupertino"   "CA"

即使您在每个市场中拥有不同数量的Compaign Name,这也应该有效.不幸的是,我认为基本选项很难实现,因为令人沮丧的是没有gregexec,尽管如果有人想出一些比较紧凑的东西,我会很好奇.